Fig. 5.

Temporal patterns of electrical activity in the LHb. Recordings from the LHb discriminated multiunit (MUA; A, C) and single unit electrical activity (SUA; B, D). MUA rhythms generally showed one peak (A) or peaks on consecutive days (C) with a circadian period. Single cells discriminated from the multiunit recordings in (A, C) are shown below them (B, D). Inset traces in (B, D) indicate the average spike waveforms for each cell; scale bars represent 15 μV (vertical) and 1 ms (horizontal). (E) Representative photograph of electrode positioning on the LHbM for electrophysiological recordings. (F) Rayleigh vector plot showing that the phases of peak electrical activity in the LHb are randomly distributed across the LD cycle. Filled circles indicate the phase of individual slices (n=18). For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.